Liquid-discharge means in bowls of centrifugal separators



Aug. 7, 1923.

- E. A. FORSBERG LIQUID DISCHARGE MEANS IN BOWLS OF GENTRIFUGAL SEPARATORS 2 Sheets-Sheo 1 Filed May 18, 1922 Aug. 7, 1923.

' E. A. FORSBERG LIQUID DISCHARGE MEANS IN BOWLS OF CENTRIFUGAL SEPARATORS Filed May 18, 1922 2 Sheets-Sheet 2 Patented Aug. 7, I923.

un tes stares @FFTCE.

SEPARATOR, OF STGCKHOLM, SWEDEN, A

CORPORATION.

LIQUID-DISCHARGE MEANS IN BOWLS OF CEN'IRIFUGAL SEPABATORS.

T 0 all whom it may concern: I

Be it known that I, ERIK AUeUsT Fons- BERG, chief engineer, a sub'ect of the King of Sweden, residing at 3 Liitzengatan, Stockholm, Sweden, have invented certain new and useful Improvements in Liquid-Discharge Means in Bowls of Centrifugal Separators, of which the followingis a specification.

In bowls of centrifugal apparatus adapted to separate liquids of, different specific weight it is frequently of importance that the discharge of one liquid or of both liquids be effected uniformly through broad openings or round the whole periphery of an opening made in a disk about/the axis of rotation of the bowl. Thereby a more even flow of the liquid is attained and the deposit of mud, if any, becomes more uniform, besides which other advantages are obtained. On account thereof the earlier method of discharging the liquid through narrow pipes has been abandoned and instead thereof the use of a so-called upper plate has been very common. Such a plate consists, as is wellknown, of an extra cap disposed inside the head. of the bowl or of an extra bottom placed above the bottom-plane of the bowl. In such case the heavier liquid is conducted between the upper plate and the head of the bowl or between the said extra bottom and the bottom of the bowl to one or more dis charge openings, while the lighter liquid is discharged through the neck of the bowl. Below only the discharge device for the heavier liquid is described for the sake of simplicity, although the .description may in certain cases also be applied to the lighter liquid. Besides only the arrangement of the upper plate in the head of the bowl. is described. The same explanation may however be brought to bear upon the location of the upper plate near-the bottom of the bowl.

The invention relates to liquid discharge means in bowls of centrifugal separators according to the above principle.

In the accompanying drawings Fig. 1 is a vertical axial section and Fig. 2 a plane view of an embodiment of the invention. Fig. 3 is a vertical axial section and Fig. 4: a plane view of another embodiment of the same.

Referring first to Figs. 1 and 2, the discharge openings D are placed comparatively Application filed May 18, 1922. Serial No. 561,898.

' near to the center of the bowl. In this embodiment said openings are in the form of broad slots made in the neck of the head of the bowl. Placed between the neck A and the upper plate B are strips C causing the liquid flowing towards the center to obtain the same speed as the bowl. Otherwise the liquid flowing inwards and coming from theperiphery, where the speed is the greatest, would tend to run faster than the bowl and on account thereof an excess in the centrifugal force would arise which would be a hinderance to the centripetal movement of the liquid. Ubviously the flowing liquid exerts a certain pressure upon said strips with the result that the flow takes place chiefly after and near the strips. This will result in that the discharge ofliquidthrough the openings, whether they consist of openings in the head or of only one central openlng, will take place chiefly at the points where the strips terminate at the openings, or in case they terminate between them, at the side of the openings following next to a strip. Consequently they desired uniformity of discharge will not be attained, but the discharge will frequently be just as irregular as in the use of discharge pipes. The said inconvenience is prevented by the aid of this invention.

In the embodiment shown in Figs. 3 and 4 the head A. is cut so as to cause the discharge to take place along the whole periphery of the opening thus formed and concentric to the axis. This opening may be made by means of a disk F provided with a packing against the bowl and a star-shaped opening G having just as many projections as the number of strips C between the head A and the upper plate B, the said disk being so positioned that the projections are situated on the same radii as the strips and so arranged. that it can only be placed in certain positions relatively to the head. Th openings I) are,so shaped that their bounding line directed towards the center is nearest to the latter in the proximity of that side E of the strips, which is following in the direction of rotation, and retires from the center at increasing distance from the strip. By choosing suitably the form of the bounding line, for instance as an Archimedean spiral, it is attained that said line coincides with an euuipotential curve in the liquid or in other words that the (inference Wards discharge openings positioned nearer in centrifugal 7 power compensates equally "for the pressure in the liquid on account of the braking action of the strip exerted on the rotationof the liquid. Under such circumstances the discharge takes place quite uniformly along the Whole periphery of the openings.

Even if this result should not be obtained in all its scope, much more uniform discharge is attained by the ahove nentioned form of the openingsthan can be effected loy means of the devices hitherto used.

What I. claim as new and desire to secu're by Letters Patent of the United States is 1. In centrifugal separators in which the liquid is conducted from the periphery to to the centerbetiveen the end ofthe bowl and a disk-like upper plate situated within said end, one or more strips being provided: 'b'etiveen the end of the bowl and the diska y k g 4 like plate, an arrangement for efi'ecting unlforn discharge oi the liquid along the Whole idth o-fthe discharge open1ngs,characteriz ed in that the inner side of the" openings is ec'c'entrlc in relation to the axis of rotation fa nd so fornied that the distance between said inner side and the axis has the least magnitude at that end of the opening '01- lowing next to a strip in the direction of rotation and increases, accordingas the distance from the strip i-1 1creases.

2. An arrangement according to claim 1, characterized by the inner side of the openings being in the' formof an Archimedean spiral. a

3. An arrangement according to claim 1 having an opening in the bowl concentric to and so arranged thatit can only be plajried certain positions relatively to the liead,

y In testimony \vhereotI afliX' my signature in presence'of two Witnesses.

ERIK AUGUST ,r oesB'ERG; lVitiiessesz 1 L. BnizesoN Luann, 1

Inez SWnNsoN. 

